In the field of ophthalmic surgery the use of lasers is well known. In laser assisted in-situ kerotomileusis pulses of laser light are used to ablate desired portions of the stromal bed following temporary removal of the outer tissues of the cornea. After replacement of the temporarily removed tissues the cornea is reshaped. During such procedure, and other ophthalmic procedures involving ablation of eye tissue, positioning and fixation of the eye against movement is important, as is proper tissue hydration, control of smoke and splatter, maintaining cleanliness of open tissues, etc. The invention disclosed and claimed herein relates to a multifunction instrument placed on the surface of the eye during ablative eye surgery to assist the ophthalmic surgeon perform laser ablative eye surgery.
In corneal surgery the use of lasers is well known. In such procedures precisely controlled pulses of laser light are used to remove thin layers of tissue by ablation. For instance, in photorefractive keratectomy (xe2x80x9cPRKxe2x80x9d) the cornea is reshaped by first removing the epithelium and Bowman""s layer (by various means) and ablating the stromal bed by laser (after which the epithelium and Bowman""s layer are left to re-form by healing). In laser assisted in-situ kerotomileusis (xe2x80x9cLASIKxe2x80x9d) the cornea is reshaped by temporarily removing the outer layers (epithelium, Bowman""s layer and a portion of the stromal bed) thereof by sharp instrument, ablating selected areas of the underlying stromal bed by laser and then replacing of the removed tissues. Various other corneal surgery are also performed using a laser to ablatively remove selected eye tissue.
These procedures encounter some common challenges. The eye must be positioned properly, and fixed against movement therefrom, so that the laser pulses are applied, consistently, to only the selected tissues. Ablation of eye tissue creates airborne plumes of smoke and splatter which can cause subsequent laser pulses to be applied non-uniformly and other adverse effects. Ablation of over-lying tissue can result in non-uniform or excess hydration of the underlying tissue which can result in total, partial and possibly non-uniform underdosage. Migration of exterior fluids into the surgical field can not only mask subsequent treatment, but can also increase the risk of infection or other contaminants.
In addition, in LASIK there are issues regarding placement of the temporarily removed tissues during administration of the laser pulses. To facilitate exact replacement of temporarily removed tissues to their original position at the conclusion of the surgery, they are typically not entirely removed at the beginning of the procedure, but rather left attached by a xe2x80x9chingexe2x80x9d of tissue (forming what is commonly called a corneal xe2x80x9cflapxe2x80x9d). During ablation this xe2x80x9cflapxe2x80x9d is typically folded over onto the sclera, where it is exposed to eye fluids, debris from ablated tissue, bacteria and other undesirable materials. In such position there is also the risk that excess eye fluids may float the flap into the laser field where it may be damaged. There is also a risk of damage to this sensitive flap during handling to replace it over the stromal bed.
Other art discloses ophthalmic tools which includes some, but not all, of the features of the multifunction tool herein disclosed and claimed. For instance U.S. Pat. No. 5,108,412 to Rosenbaum et al discloses a suction ring for attachment to the sclera in the limbus plane. This apparatus is used to guide a trepan perpendicularly to the limbus plane. In U.S. Pat. No. 5,980,543 to Carriazo et al a similar suction ring is used to guide a microkeratome parallel to the limbus. In neither of these patents is the suction ring used to fix the position of the eye in relation to a laser or structure not attached to the ring. In neither of these patents does the suction ring include a platform for xe2x80x9cstoragexe2x80x9d and replacement of a corneal flap during a surgical procedure. In neither of these patents are other attributes of the invention, such as plume and splatter evacuation means, means for creating flow of dehydrating gas over the aperture of the ring, means for improved irrigation for a surgical field, etc., disclosed.
Likewise U.S. Pat. Nos. 5,941, 873 and 5,971,977 to Korenfeld shows one, but not other, attributes of the invention disclosed and claimed herein. In these patents there is disclosed a device having a ring-shaped tube with a plurality of apertures disposed about the inner circumference thereof, to aid in smoke removal during an ablative procedure of the eye. These patents do not teach any structure for aspirating fluid away from an open stromal bed nor do they teach a sterile platform on which to repose a corneal flap during an ablative procedure of the eye.
The invention disclosed and claimed herein is a multifunction surgical instrument directed to each of the above-mentioned issues. It provides a means for fixing the position of the eye, as may be required, during surgery. It provides a means for controlling hydration of open and/or ablated eye tissue during surgery. It provides a means to aspirate fluids containing ablative debris from the surgical field. It provides a means to prevent potentially contaminated fluids from migrating from outside to the inside of the surgical field.
Also provided is a sterile platform, elevated above potentially contaminating fluids, upon which to repose a corneal flap (and protect it from smoke and splatters) during surgery. The invention disclosed also provides means for removing smoke resulting from ablation of tissue. Thus the invention disclosed and claimed herein is directed not only to more uniform and consistent application of laser pulses (by establishing good fixation of the eye, removing excess hydration and smoke from the surgical field) but better protects open and/or ablated tissue from contaminating debris and/or bacteria.